These are some of the frequently Used Unix Commands which may be of help to you. have a look
Starting and Ending
login: `Logging in'
ssh: Connect to another machine
logout: `Logging out'
emacs: `Using the emacs text editor'
mkdir: `Creating a directory'
cd: `Changing your current working directory'
ls: `Finding out what files you have'
cp: `Making a copy of a file'
mv: `Changing the name of a file'
rm: `Getting rid of unwanted files'
chmod: `Controlling access to your files'
cmp: Comparing two files
wc: Word, line, and character count
compress: Compress a file
e-mail: `Sending and receiving electronic mail'
talk: Talk to another user
write: Write messages to another user
sftp: Secure file transfer protocol
man: Manual pages
quota -v: Finding out your available disk space quota
ical: `Using the Ical personal organizer'
finger: Getting information about a user
passwd: Changing your password
who: Finding out who's logged on
lprm: Removing a print job
lpq: Checking the print queues
ps: `Finding your processes'
kill: `Killing a process'
nohup: Continuing a job after logout
nice: Changing the priority of a job
&: `What is a background process?'
Cntrl-z: Suspending a process
fg: `Resuming a suspended process'